Dell U4919DW / MacBook pro 5k issue

The current work-around is still using the PBP mode and connecting two cables to the Mini or the Macbook Pro, one with USB-C, the other with USB-C to DP. Both DELL and Philips support PBP. This will give you two monitors with 2560x1440. You also have to switch off the "Monitors use different Spaces" mode in "Mission Control" to prevent windows from being cut while moving them to the center ofthe screen.

As far as I understand this issue, Apple limits the pixel frequency to about 250 MHz which is enough for 3840x1080@60Hz or 5120x1440@30Hz. I tried different custom resolutions with SwichResX and nothing works above this 250 MHz. For 5120x1440@60Hz you need 442 MHz. But as we know from Bootcamp users, it's a macOS software limitation.

All this discussion about what port may support the display is pretty useless as it's obviously just a software issue. Booting into Windows with Bootcamp makes the display work with any connection (USB-C alt mode or adapter). Apple just needs to push a proper fix for the (at least Intel) driver. It could be possible that several adapters with their own drivers or also the Radeon GPU can already work with that display, but thats not because of a hardware capability but just because of a functioning driver.

If you want to stay with your 13" MBP / Mac Mini 2018 - yes, it is.

And it is an Apple driver issue, not one of the Intel Graphics chipset - on the same machine it works flawlessly with Windows 10 with 5120 by 1440 oob.

JeanLuc7 wrote:

If you want to stay with your 13" MBP / Mac Mini 2018 - yes, it is.

And it is an Apple driver issue, not one of the Intel Graphics chipset - on the same machine it works flawlessly with Windows 10 with 5120 by 1440 oob.

I just received a moshi USB-C to DP cable. I tried it with my USB-C thunderbolt cable w/ my 2018 13" MBP and I could not get resolution 5120 x 1440. It did now show the resolution 2560x1440. It would only show 3840 x 1080 for both monitors. I'm not sure what I did wrong but I could not get that work.

marino389 wrote:

Can anyone confirm this for me?

I'm looking at purchasing a MacBook Pro that will be compatible with the U4919DW monitor. I want it to work properly without any "workarounds." Full resolution out of the box. My understanding from this thread is that it must be a dedicated graphics card instead of the integrated one.

I talked to Apple sales today and I was told that ALL 13" MBPs (without exception) have integrated cards. And that ALL 15" MBPs (without exception) have dedicated cards. I was also told that you cannot customize a 13" to have a dedicated card.

Is this correct?

If you want it to just work you will need to purchase a 15" MBP. It will work without problems. It does not work directly with a MBP 13", for no other reason than Apple will not create a display overlay for it. It works just fine w/ a MBP 13" running Windows 10. So its MacOS not the hardware.

I update my MacBook Pro 15" with Catalina and now I can choose 5120*1440 in the setting. Before, I used ResXtreme but now it's like working without the app.

But there is not a difference in quality between before with the application ResXstrem and now via the native settings.

On my Macbook Air 2018 the Problem still persists with Catalina 10.15.1. The maximum resolution with the thunderbolt cable is still 3840x1080 but under Windows Bootcamp I get the full 5120x1440. Please apple, fix it. It's annoying not be able to use the real resolution.

The numbers shown is the "scaled" Box are NOT actual resolutions. they are the "text will look like" numbers. To get actual resolutions, you must look elsewhere, such as:

 Menu > About this Mac > (system report) > Graphics & Displays

Grant, you are wrong. In fyan's case, a 5120x1440 resolution is shrinked on 3840x1080 by the OS, and then again it is zoomed to 5120x1440 by the monitor. This looks horrible. You may compare it to a FullHD movie scaled down to SD and then shown on a HD TV.

As far as I know, the only way to get the combination "Intel UHD 630 - MacOS - 49" display with 5120x1440" is using the Picture-by-Picture mode. I can not stress clearly enough that everything works out of one piece, if the operating system is called "Windows".

I noticed today in macOS Catalina 10.15.2 there is a new override file at

/System/Library/Displays/Contents/Resources/Overrides/DisplayVendorID-1e6d/DisplayProductID-9e7b

It contains a single element "DisplayPixelDimensions" set to 5120x1440.

Is this for the LG 49BL95C-W display?

Does it fix the problem?

Will a similar override for the other similar displays fix those displays?

To know for sure what resolution and frequency a display is set to, you must check the onscreen menu of the display. If it doesn't have all the information then you can use SwitchResX to view the timing information of the current resolution be double clicking the current resolution in the Current Resolutions list.

To know how your display is connected to the computer (DisplayPort speed and lanes) and to get the unaltered EDID (which SwitchResX does not show) or the EDID of both DisplayPort connections of a dual link SST display (like the LG UltraFine 5K), then use the following command:

/System/Library/Extensions/AppleGraphicsControl.kext/Contents/MacOS/AGDCDiagnose -a > AGDCDiagnose_a.txt 2>&1

Each connection might have a different EDID, so you might want to do it for all the ports of a display.

Of course Catalina 10.15.2 doesn't work with the Dell. Instead of fixing the problem, Apple created a work around that only works with the LG display.

You need to copy the file Apple made for the LG display into the Dell folder. Rename the file using the product ID of the Dell display. Edit the DisplayVendorID and DisplayProductID instead the file with the IDs for the Dell display.

The Dell folder is DisplayVendorID-10ac. The Dell DisplayVendorID is 4268 decimal.

Use the AGDCDiagnose command and post the result so we can look at the EDID (just need the EDID part if there's no file uploads here). Don't forget to mention the display model and how it's connected. There might be different EDIDs for different connection types (different ports - HDMI, DisplayPort 1, DisplayPort 2, etc.) or different modes (DisplayPort 1.2, DisplayPort 1.4, PbP, etc.). So get the EDID of each and post the unique ones.

In Catalina, you may need to allow write capability to root to modify the overrides folder.

sudo mount -uw /

I use the script at https://gist.github.com/joevt/32e5efffe3459958759fb702579b9529

to load multiple EDIDs from different sources (for example, if you created files AGDCDiagnoseDisplayPort1.txt, AGDCDiagnoseDisplayPort2.txt, AGDCDiagnoseDisplayHDMI.txt, etc.) then you can do the following:

source EDIDUtil.sh
loadagdcfile AGDCDiagnose*.txt
listedids

It will group all the duplicate EDIDs together and list the sources of each EDID (which file(s) it was loaded from).

It's got nothing to do with the hardware, put Windows or Linux on the same machine and it'll work straight away at the correct resolution.

MacOS does not support the extended portion of the EDID profile the defines the native resolution and thats due to the 1.3 spec stating that 4096 is the largest width expected.

I'm currently running 4096x1440@70hz on my 49" Philips on a 2015 Macbook with Intel graphics.

Pinkie promise it's working just fine with bootcamp :-)

Macbook Mini 2018, U4919DW - Fresh install of windows 10 on bootcamp (10 mins ago to show this). USB-C to USB-C.

Despite my photos, the screen is crystal clear. Not like the blurry scaled screen on OSX.

The hardware of the Mac Mini 2018 works just fine with the 49" Dell, OSX is lacking.

Minor correction to previous post https://discussions.apple.com/thread/8641919?answerId=251812380022#251812380022

I had said that Apple rewrote HT202351. Actually what they did was redirected HT206587 to HT202351 and deleted HT206587. You can find HT206587 at https://web.archive.org/web/20191123020413/https://support.apple.com/en-us/HT206587

I created a patch for my Macmini8,1 (macOS Catalina 10.15.2) to allow resolutions greater than 4096 wide but it's not showing an image for timings wider than 4200. I can take screenshots though (I tested up to 5120x900). I'm not sure if the problem is with my adapter or the driver. I only tried 4104 which works. I should try more values to find the exact limit between 4104 and 4200. I could not find a significant difference in the log stream output between switching from 4096 to 4104 and switching from 4096 to 4200. The log stream command was mentioned at https://discussions.apple.com/thread/8641919?answerId=251812762022#251812762022

Before trying the patch, make a backup of /System/Library/Extensions/AppleIntelCFLGraphicsFramebuffer.kext. I think you might need to disable SIP.

sudo mount -uw /
IFS=$'\n'
for thefile in $(find /System/Library/Extensions -name 'AppleIntelCFLGraphicsFramebuffer'); do
	printf "Patching $thefile\n"
	sudo perl -i.bak -pe '$before = qr"(\x83\xc9)\x04(\xC1\xE1\x0A)"s;s/$before/$1\x08$2/g' $thefile
	printf "Re-signing $thefile\n"
	sudo codesign -f -s - $thefile
done
sudo touch /System/Library/Extensions
sudo kextcache -i /

If your Mac doesn't use AppleIntelCFLGraphicsFramebuffer then you might need a different patch. The patch modifies the width check in AppleIntelFramebuffer::ValidateSourceSize(IODetailedTimingInformationV2*). The original check is for 4096 or 5120 for when multilink flag is set. I changed it to 8192 and 9216.

There is a height check for ≤ 2880 pixels near the width check that I did not change.

The function outputs a message to log when the width or height is exceeded:

"[IGFB][INFO   ] FB%d: Mode with width %d and max %d rejected with multilink set to %d\n"